Grant Gustin, the actor better known as the star of the CW’s The Flash, is not having it.

Someone leaking a photo this week of Gustin’s altered costume for the superhero drama’s upcoming fifth season was bad enough. (It’s since been deleted from social media.) Even worse, the image was up long enough for some fans to determine they didn’t like the new look. Some of those people also weighed in on Gustin’s appearance, which, it turns out, is a sore spot for him.

Grant Gustin wears his costume on The Flash set in Vancouver last month. (Photo: JKing/Backgrid USA)

Grant Gustin promotes The Flash during Comic-Con International 2018 on July 21 in San Diego. (Photo: Araya Diaz/Getty Images)

The 28-year-old addressed the subject in a short video, in which he was clearly frustrated, as well as a post on Instagram.

The actor said in his post that people have told him and his parents for most of his life that he was too thin. “I’ve had my own journey of accepting it,” Gustin wrote. “But there’s a double standard where it’s ok to talk s*** about a dude’s body. I do my best to stay in shape and add as much size as I can through out these seasons. I’m naturally thin, and my appetite is greatly affected by stress.” The result is that it’s difficult for Gustin to gain weight.

“I’m happy with my body and who I am and other kids who are built like me and thinner than me should be able to feel the same way,” Gustin wrote in part of his lengthy post. “Not only that, but they should be able to feel like THEY could be a superhero on tv or film or whatever it may be someday.”

As much as Gustin dislikes the focus on his physique, he emphasized his approval of the tweaks to his superhero garb, which he said is still a work in progress. A more complete version will star alongside Gustin when The Flash returns to the CW on Oct. 9.